Seepage of Oil

[Captain Morgan]

I was checking things out after a drive and found a bit of oil saturating the area around where the transmission mounts up with the engine. It's not actively dripping but it's pretty wet. Is this common for an older car or should I be budgeting new gaskets and seals? This car is newly in my custody and I'm trying to assess the problems.

 

[Don C]

I would make sure where it's coming from before you start tearing it apart, unless you're planning on overhauling the engine. It looks like it may be coming from further up, like the rear seal between the intake manifold and the valley, or the oil pressure switch/sensor.

 

[Hemikiller]

From that photo, it could be a lot of things. Judging by the oil on the block, it's a safe bet you can start with a set of valve cover gaskets. If there's a puddle of oil on the top of the block behind the intake, then as DonC noted, your intake gasket and/or oil sensor are suspect. Beyond that, you'd need to clean it up well and then ascertain where the oil is coming from. 

 

[Captain Morgan]

Thanks for the tips. I’ll try and take a look in the next few days. The engine has 98,000 miles on it and it hasn’t been driven often for the last 20 or so years. I am betting it’s going to need a little more work than I had hoped for.

 

[cv_72mustang]

Thanks for the tips. I’ll try and take a look in the next few days. The engine has 98,000 miles on it and it hasn’t been driven often for the last 20 or so years. I am betting it’s going to need a little more work than I had hoped for.

I have the same thing going on it was the rear gasket on the intake manifold. It's original and believe it was cork material. Was gonna to replace just the intake gaskets but now I'm thinking I might have engine rebuild and the tranny.  I'm keeping the car and nothing been done since it was built in 72. 

 

[Captain Morgan]

I have the same thing going on it was the rear gasket on the intake manifold. It's original and believe it was cork material. Was gonna to replace just the intake gaskets but now I'm thinking I might have engine rebuild and the tranny.  I'm keeping the car and nothing been done since it was built in 72. 

That is exactly my situation as well. Since I’ll have to change the gasket, I have been wanting to replace the intake manifold with an Edelbrock Performer and a 4 barrel carb. I’m going to dig into it in the next few days. I’ll let you know what I find.

 

[Twins]

I had a similar situation which progressed to  some actual oil drips.  For some time I assumed it was coming from the lower part of the engine and was expecting a big issue.

As Don mentioned, in my case it was only the oil pressure sending unit located just behind the intake manifold on top of the engine.  Replaced and tightened and no more seepage or leaks!

 

[Captain Morgan]

Just an update. From what I can tell, it looks like the oil is coming from the valve cover gaskets. If this is indeed the culprit, I can live with that problem. Now my transmission... that’s another story.

 

[Mac]

As far as your transmission, if it is an FMX, chances are it is leaking from the shifter seal.  There is a complete step by step on how to replace this seal and respective o-ring in the maintenance section of this web site.

Mac

 

[cv_72mustang]

Update on my leak.  I thought it was a sticking PCV NO or the china wall gasket for sure, NO.  It was the darn oil sender.   Took a bunch of tries to find reason and leak location.  Didn't leak after a bunch of small test drives <5 mile over a few days after cleanup of PCV.  WTF.  Finally caught it by wrapping the base of sensor with white cotton cord.  I started to remove with an adjustable wrench  but looked like it might strip.  Bought the tool , 1 1/16  socket .  No tread compound (guess not after 48 years) but bought new one anyway. We'll see after a few days. 

 

[Twins]

Exactly what my leak was and the cure was the same.  Good for you.  Hopefully your problem is solved.

 

[Carolina_Mountain_Mustangs]

One thing you mentioned was the mileage on your engine. When you had the valve covers off did you find any pieces of black hard rubber laying in the head. Did you look through the valve springs at your valve stem seals. They get hard and brittle with age. The pieces can get in oil pan and block the oil pump screen can get into oil pump on some models and either lock it up braking the drive shaft to it or can lock up the pressure relief valve and explode the oil filter. You can change the seals without pulling heads but not super easy. You hold valves closed with air pressure and special tool to compress the springs and remove valve keepers to get to the seals.